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Biomedical subjects

G Godeau

Publications and source records attributed to G Godeau.

88 records · Page 5Linked to original sources
PubMed1982

Isolation and partial characterization of an elastase-type protease in human vulva fibroblasts: its possible involvement in vulvar elastic tissue destruction of patients with lichen sclerosus et atrophicus.

A complete disappearance of orcein positive material was observed in the superficial dermis of patients suffering from Lichen sclerosus et atrophicus. An elastase-type protease was isolated and partially purified from Triton X-100 extracts of human vulvar fibroblasts by gel permeation chromatography. It presents the characteristics of a metalloenzyme hydrolyzing Succinoyl-tri-alanine paranitroanilide maximally at pH 8.0 and is also active towards insoluble elastin. When partially purified enzyme is directly applied on to rabbit skin sections or when injected intradermally to young rabbits, it produces appreciable degradation of elastic fibers. The involvement of this protease in the disappearance of elastic fibers in Lichen sclerosus et atrophicus is postulated.

Adult↗
PubMed1981

Studies on elastic tissue of aorta in aortic dissections and Marfan syndrome.

Insoluble elastins were isolated from control and aneurytic aortas by a sequential extraction procedure involving the use of purified collagenase. Marked differences in amino acid analyses and susceptibilities to pancreatic elastase were observed between normal and pathological samples. The incorporation of either 14C-lysine or 14C-glucosamine into proteins of the vessel wall was also studied. In addition, high amounts of elastase-type activity was extractable from pathological aorta specimens which may contribute significantly to the loss of elastic tissue evidenced by ultra-structural studies and confirmed by the biochemical technics. We propose therefore that increased elastase-type protease activity in these pathological aortas does significantly contribute to the weakening of the aortic wall and also may well be the main cause of the rupture of aneurysms observed occasionally.

Adult↗
PubMed1981

Pharmacological studies on elastin peptides (kappa-elastin). Blood clearance, percutaneous penetration and tissue distribution.

Soluble elastin peptides obtained by partial hydrolysis of ligamentum nuchae elastin in 1M KOH in 80 per cent aqueous ethanol (kappa-elastin) were labelled in vitro by incubation with tritiated borohydrate. 3H-labelled kappa-elastin was administered iv and percutaneously and its elimination and organ distribution determined. iv administered kappa-elastin is rapidly eliminated through the kidneys with a first rapid phase (t 1/2 9.9 min) and a second slower phase (t 1/2 169 min). Percutaneously administered elastin peptides penetrate in the dermis and 30 to 40 per cent of the administered label can still be found in the skin 48 hours later. Resorption through the skin is a slow process, with very little or no radioactivity detectable at any time in the blood. Only liver and lung contained significant amounts of radioactivity (4 per cent and 2 per cent of the total dose administered) at 48 hours after administration. Urinary elimination represented about 5 per cent of the administered dose. Histochemical studies performed on the skin of rats treated daily with kappa-elastin (25 mg per day for 4 weeks) showed an increase of elastin-staining material in the dermis. This increase is partly due to a modified staining of collagen bundles, resulting probably from the association of elastin peptides with the collagen bundles. It may also partly be due to an increase of elastin fibers in the dermis through the stimulation of fibroblast activity. These histochemical results confirm the penetration of elastin peptides in the dermis, their association with dermal collagen fibers and also their action on the cellular activity of the dermis.

Administration, Topical↗
PubMed1980

Biodegradable arterial prosthesis from rat aorta.

The preparation and potential clinical use of biodegradable microarterial grafts from rat aorta were investigated. Trypsin treated arterial segments were coated with heparin or chondroitin sulfate to reduce thrombogenicity. The samples were crosslinked with formaldehyde vapors at 4 degrees C. 50 - 100 microgram glycosaminoglycans taken up per mg aorta dry weight were resistant to washing with water for 24 hrs. The covalent crosslinks introduced by formaldehyde and resistance of the grafts to proteolytic degradation. The treated grafts were implanted on 70 rats in an infrarenal aortic position. The permeability of the aldehyde crosslinked prosthesis after 21 days by patency test was lower than the patency ratio measured with fresh autologous grafts. The glycosaminoglycans associated with the prosthesis improve the patency of the crosslinked grafts by about 48%. The resistance to bacterial collagenase of the excised grafts decreased with progressing time of implantation. In the permeable prosthesis and in the contiguous aorta, elastolytic activity was demonstrated by radial diffusion in elastin-agar gels. The grafts removed after 21 days of implantation were surrounded with scar tissue. In contrast to fresh aorta, the macromolecular hydroxyprolin in the scar was readily solubilized with pepsin. The presence of the fragmented elastin and collagen fibers in the excised graft is in favour of their resorption "in vivo".

Animals↗
PubMed1979

Mechanism of action of collagenase on the blood-brain barrier permeability. Increase of endothelial cell pinocytotic activity as shown with horse-radish peroxidase as a tracer.

The ultrastructural mechanism of the protease induced blood-brain barrier permeability-increase was studied with horse-radish peroxidase as a tracer. After intravenous injection of collagenase or pronase, a significantly increased number of pinocytotic vesicles was found in brain capillary endothelial cells. alpha-Chymotrypsine did not exert such an action.

Animals↗
PubMed1979

Quantitative evaluation of the in vitro biosynthesis of gastric mucus glycoproteins. Standardization of the methodology.

For the evaluation of a normal or pathological function of gastric mucosa, a reproducible method for the estimation of the biosynthesis of mucus glycoproteins appears to be necessary. Rat gastric mucosal scrapings incorporate in vitro several labeled compounds such as 14C-U-D-glucose, 35SO4, 14C-I-L-fucose and L-G-3H-proline in glycoproteins similar to those synthetized in vivo by native mucosa. The aim of our present work is to describe in detail the procedure we use and to show its reproducibility in 9 separate experiments. Secreted glycoproteins (fraction II) and intracellular glycoproteins (fraction III) obtained during a 4 hours in vitro incubation of rat gastric mucosal scrapings at 37 degrees C in standardized conditions were separately studied. The protein and hexose contents, total incorporated radioactivity and specific radioactivity (cpm/mg protein) were determined in these two fractions. The protein content of fraction II from 2 rat gastric mucosal scrapings incubated in 5 ml was 2 mg +/- 0.4 SEM and its hexose was 38.7 mg per 100 mg protein +/- 3.9. Fraction III contained 6.3 mg protein +/- 1.3 and 15.7 mg hexose per 100 mg protein +/- 3.5. About 27% of the total radioactivity incorporated (from 14C-glucose) was in fraction II (+/- 2.6 SEM) and 73% (+/- 2.6 SEM) in the cell bound fraction III. The distribution of total radioactivity was quite similar to that of total proteins : about 25% proteins were in fraction II and 75% in fraction III with a SEM of about 5 to 10% of the average value. If the biosynthetic activity is expressed as specific radioactivity, i.e. the ratio of incorporated radioactivity to mg proteins, the average for both fraction II and fraction III was about 10,000 cpm/mg protein and the standard error of the mean values are +/- 5.2% of the mean for in vitro secreted mucus glycoproteins (fraction II) and 9.1% in the case of intracellular glycoproteins (fraction III). These values can be considered as a satisfactory index of reproducibility of the method of mucosal scrapings if performed as described above.

Animals↗
PubMed1977

Action of anthocyanosides of Vaccinium myrtillis on the permeability of the blood brain barrier.

Proteases and especially collagenase injected into the lateral brain ventricles of rats are able to increase the permeability of the blood-brain barrier to trypan blue. Treatment of the rats with anthocyanosides of Vaccinium myrtillis diminishes the permeability increasing effect of collagenase and accelerate the recovery of normal permeability. This effect seems to be related to a less effective enzymatic attack on collagen, as hydroxyproline content in the CSF is increased less after collagenase injection in treated animals than in untreated controls.

Animals↗
PubMed1976

Biochemical studies on dacron arterial prostheses.

Dacron arterial prostheses, treated or not with biopolymers (gelatin, glycosaminoglycans) were implanted in the abdominal aorta of dogs and the connective tissue synthetised inside and outside the prosthesis was studied. After 3 and 9 months of implantation the prosthesis, a joining portion and a piece of aorta were excised and put in organ culture with 14C-lysine for 3 days. Representative macromolecular extracts were then obtained by a "chemical dissection" procedure. The radioactivity and the chemical composition of these extracts was studied. The DNA content of the prosthesis was higher than that of the adjacent aorta showing a dense cellular repopulation of the prosthesis. This was confirmed by histology also which revealed the presence of a newly formed limiting elastic membrane and the presence of numerous elastic fibrils. Collagen, elastin and glycosaminoglycans could be detected in the macromolecular extracts showing that the cells which repopulated the prosthesis expressed a complete biosynthetic capacity as far as matrix macromolecules are concerned. The distribution of proteins in the extracts was as follows: 4% of total proteins were extracted in a 1M CaCl2-buffer 80% of total proteins in the collagenase extracts, 10% in the 6M urea extract. Only 0,2% of proteins were in the final elastase extract, 10 times less than in the joining aorta fragment. The proportion of the other proteins was similar in aorta and in the prosthesis as well as the chemical composition (hexosamine and hydroxyproline content) of the extracts. The proportion of collagenase-extractable proteins decreased with the time of implantation (from 3 to 9 months) and the proportion of urea-extractable proteins increased. This type of modification is similar to that found in aging aorta wall. 14C-lysine was actively incorporated in all macromolecular fractions studied. The incorporation pattern of the prothesis tissue was similar to that found for the joining host aorta, showing a similar regulatory tendency for matrix macromolecules. It appears therefore that a valid hemocompatible vascular type of connective tissue can be synthesised on the dacron arterial prosthesis and nature of this connective tissue can be influenced by previous biopolymer treatment of the synthetic prosthesis. The described procedure (incorporation of labelled precursors in organ culture) appears to be a valid method for the exploration of the regulatory processes underlying the synthetic capacity for matrix macromolecules of the newly formed tissue in the synthetic prosthesis.

Animals↗
PubMedDate not supplied

Congenital soft tissue dysplasias: a morphological and biochemical study.

The term congenital soft tissue dysplasias (CSTDs) regroups some localized malformations of covering soft tissues in children, presenting as various clinical entities, either recognized as particular syndromes (e.g., Parkes-Weber, Klippel-Trenaunay, Proteus) or, most often, appearing less stereotyped (e.g., segmental hypertrophy or gigantism, lymphedema, angiodysplasia, phakomatosis), with a common histopathological lesion, the hamartoma. The aim of this paper is to report a morphological and biochemical study of the extracellular matrix of skin and subcutaneous tissue in children with CSTD. For every patient, pathological tissues were compared with contralateral, symmetrical tissues, taken as controls. In all CSTDs, pathological samples were characterized by an increase in water and total glycosaminoglycan (GAG) content with a decrease in collagen content. Other results lead the authors to distinguish two main entities, segmental dysplasia (SeD) and neuroectodermal dysplasia (NeD). Elastic fiber content was increased in SeD and decreased in NeD. Hyaluronic acid (HA) and dermatan sulfate (DS) were increased in NeD, whereas in SeD, HA was decreased with an increase in the DS/HA ratio. Cultured fibroblasts from dysplastic skin had slower proliferation in vitro than fibroblasts from control skin, whereas their biosynthetic activity concerning collagen and GAGs was greater. The difference in the composition of extracellular matrix supports the clinical classification of CSTDs in two main groups: segmental dysplasia with or without gigantism and neuroectodermal dysplasia (in von Recklinghausen's disease and nevi).

Abnormalities, Multiple↗